1. Field of the Invention
The present invention relates to a system and method for homogenizing production fluid from an oil well having gas slugging, for the purpose of improving the flow characteristics of the well.
2. Description of the Related Art
In long horizontal liquid wells with a gas cap, the gas may influx into the wellbore. As it travels the horizontal length, the gas tends to segregate and migrate upwardly from the liquid, collecting and forming high pressure gas bubbles generally referred to as gas slugs. As the well turns vertically at a heel portion and continues upwardly to the surface, the segregated gas will have a tendency to form large gas slugs in the liquid medium and possibly risk killing the well due to slugging flow, and upsetting the surface facilities and related systems.
Horizontal Wells
In long horizontal wells, the fluid flow has a tendency to segregate, with lighter fluids and gas drifting toward the top of the horizontal borehole and heavier liquids settling toward the bottom. At the heel of the well, the gas and liquids may be significantly segregated such that the segregated gas may be in slug form and provide an imbalance in the fluid lift, thereby potentially killing the well from flowing naturally. Remediation of the well would then be required to restart the well. In addition, the gas slugs passing through surface equipment can upset the surface facilities and related systems, thereby making it difficult to efficiently process the produced liquid hydrocarbons from the well.
Various arrangements for separating gas from production fluids in such wells downhole are known. For example, U.S. Pat. No. 5,431,228 relates to a downhole gas-liquid separator for wells, in which gas is separated from production liquids by way of a shaped baffle disposed in the well between the distal end of the production tubing string and the point of entry of gas and liquid into the wellbore. The gas and the liquid are then directed to the surface via separate flowpaths.
U.S. Pat. No. 5,482,117 is directed to a gas-liquid separator for use in conjunction with downhole motor driven pumps, particularly electric motor driven submersible pumps. A baffle is disposed in a tubular housing for separating gas from liquid.
Although such prior art systems represent attempts to separate gas from liquid downhole, the problems associated with gas slugging continues to hamper production in such gaseous slug-laden wells.
The present invention relates to a method and system of homogenizing the production fluid from such gaseous slug-laden wells, particularly wherein the gas slugging is at least in part due to the presence of one or more horizontal, or near horizontal boreholes communicating with the primary vertical borehole. A system for homogenizing production fluid from such wells is also disclosed.